Existing multimedia applications offered in a multimedia communication system do not support security in the media plane. Concern over media plane security is a relatively new problem.
Existing proposals in a multimedia communication system such as the Internet Protocol (IP) Multimedia Subsystem (IMS) are based on some kind of token based symmetric key methods, managed using a key management server that potentially creates and distributes keys. 3GPP (3rd Generation Partnership Project) Technical Report (TR) 33.828, the disclosure of which is incorporated by reference herein, discusses existing proposals for IMS media plane encryption. However, these existing solutions are not scalable (since the server should be highly available and online all the time), do not provide authentication of entities, and, in addition, escrow keys at the server.
Conversely, non-IMS applications such as SKYPE (tradename of Skype Technologies S.A. of Luxembourg) and other client-to-client multimedia applications provide end-to-end privacy with authentication and no key-escrow. However, the solution relies of the use of certificates which require a highly available public key infrastructure (PKI) which is extremely expensive to manage. Moreover, the solution does not scale well for group conferencing applications, nor does it provide for lawful intercept of communications in the absence of a PKI.
Furthermore, similar key management security concerns exist in conferencing systems where parties participate in call sessions through a conference server.
Thus, a need exists for a secure key management solution for use in communication environments such as a media plane of a multimedia communication system and a call conferencing system.